Histone modifications in transcriptional regulation by alcohol dependence

描述(申请人提供)：强迫性(依赖)饮酒背后的神经生物学机制涉及大脑回路的渐进性失调，这些回路削弱了奖励、压力和动机。虽然组蛋白修饰在历史上被认为是静态的，但越来越多的证据显示出一种意想不到的可塑性，并表明由于组蛋白调节改变而导致的基因表达的长期变化在原则上可能是可逆的。在有丝分裂后的神经元中，组蛋白修饰正在成为学习和记忆以及药物滥用效应等过程中的潜在参与者。因此，本提案中正在测试的假设是，大脑区域中长期的组蛋白翻译后修饰，以削弱奖励、压力和动机，是导致过度饮酒的神经适应的关键。为了验证这一假说，本提案将对以下两种情况进行全基因组研究：1)慢性间歇性暴露(CIE)，这是一种整个INIA财团提出的依赖相关饮酒增加的范式；2)操纵G蛋白β1亚单位(0(31)的水平，这被INIA财团确定为酒精饮酒的直接调节染色质动态的调节因子。然后，我们将扩大对组蛋白修饰的研究，这些差异调控基因被确定为与染色质状态相关的其他组蛋白标记，以定义以过度饮酒为特征的组蛋白修饰谱系。最后，我们将用生化、形态和行为策略来验证在差异调控基因中观察到的组蛋白修饰模式的功能意义。对于跨基因组和特定基因的组蛋白修饰的定位和定量，我们将分别使用染色质免疫沉淀和平铺阵列(ChlP-Chip)或定量实时PCR(ChlP-PCR)。数据将与整个INIA财团产生的基因表达、行为和药理学数据整合在一起。本项目的研究结果将为过量饮酒的神经生物学的综合系统生物学分析奠定基础。

DESCRIPTION (provided by applicant): The neurobiological mechanisms behind compulsive (dependent) alcohol intake involve a progressive dysregulation of brain circuits that subserve reward, stress and motivation. While histone modifications were historically considered static, mounting evidence is revealing an unexpected degree of plasticity and suggests that long-lasting changes in gene expression due to altered histone regulation may, in principle, be reversible. In post-mitotic neurons, histone modifications are emerging as potential players in processes like learning and memory and the effects of drugs of abuse. Thus, the hypothesis under test in the present proposal is that long-lasting post-translational histone modifications in brain regions that subserve reward, stress and motivation are key to the neuroadaptations that underlie excessive alcohol consumption. To test this hypothesis, the present proposal will conduct a genome-wide investigation of changes of selected activation and repression histone marks induced by alcohol dependence in 1) chronic intermittent exposure (CIE), a paradigm of dependence-associated increased drinking that is proposed throughout the INIA consortium; and 2) mice with manipulation of the level of the G protein beta 1 subunit (0(31), which was identified by the INIA consortium as a regulator of alcohol drinking that can directly regulate chromatin dynamics. We will then expand the investigation of histone modifications at the differentially regulated genes identified to additional histone marks associated with chromatin states to define the repertoire of histone modifications that characterizes excessive alcohol intake. Lastly, we will validate the functional significance of the patterns of histone modifications observed at the differentially regulated genes with biochemical, morphological and behavioral strategies. For the mapping and quantitation of histone modifications across the genome and at specific genes, we will use chromatin immunoprecipitation coupled with tiling arrays (ChlP-Chip) or quantitative real time PCR (ChlP-PCR), respectively. Data will be integrated with gene expression, behavioral and pharmacological data generated across the INIA consortium. The results of this project will contribute to lay the foundation for an integrated systems biology analysis of the neurobiology of excessive alcohol consumption